Blend or mortar-pestle together basil, olive oil, lemon juice, and a pinch of salt until smooth. Set aside — or strain for a clearer oil.
Prepare the fish:
Pat the coley fillets dry and season with salt, pepper, and lemon zest.
Press the top side of each fillet into the coarse semolina to coat lightly.
Heat olive oil (or oil + butter) in a non-stick pan. Place fillets semolina-side down first and cook for about 3–4 minutes until golden and crisp. Flip and cook another 2–3 minutes until just done.
Sauté the vegetables:
In another pan, heat a splash of olive oil. Add garlic and let it sizzle briefly.
Add asparagus and courgette, season, and sauté until just tender but still vibrant. Deglaze with a splash of white wine or lemon juice if desired.
Plate:
Arrange the warm courgette and asparagus mix on each plate.
Top with crispy coley fillets.
Drizzle with basil-lemon oil and garnish with extra fresh basil or microgreens.